Vein Scanner with User Interface for Controlling Imaging Parameters

ABSTRACT

A portable handheld vein-image-enhancing device broadly includes: a first laser emitting a beam of light at a first wavelength; a second laser emitting a beam of light at a second wavelength; a scanner to scan the beams of light onto the target surface; a photo detector to receive the reflected vein image and convert the image into a signal, for use by the second laser and scanner to project the image onto the target surface; and a user interface and electronic circuitry to permit adjustments to one or more of the following imaging parameters: a vein size parameter to set a vein size to be imaged by the device; a field of view size; a size for a field of high resolution for the projected image; a brightness of the projected image; and a laser output intensity parameter setting a depth of penetration by the first wavelength for the imaging.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/910,257, which is a continuation of U.S. patent application Ser. No.11/807,359, now issued as U.S. Pat. No. 8,489,178, which claims priorityon U.S. Provisional Patent Application Ser. No. 60/898,506, filed Jan.31, 2007, and on U.S. Provisional Patent Application Ser. No. 60/817,623filed Jun. 29, 2006, and which parent application is also acontinuation-in-part of U.S. patent application Ser. No. 11/700,729filed Jan. 31, 2007, and U.S. patent application Ser. No. 11/478,322,filed on Jun. 29, 2006. The disclosures of each of these applicationsare incorporated herein by reference.

FIELD OF INVENTION

In these applications, technology, embodiments and ergonomics of aminiature vein enhancement system is described that uses scanned lasersand other light sources to accomplish the acquisition and projection ofa vein pattern to aid the user in locating a vein for venipuncture. Inthis application, additional capabilities and how these capabilitiesimprove the processes associated with venipuncture are set forth.

Key among these is the use of enhanced embodiments that allow additionaldata collection and application processes that are critical to thesuccessful performance of venipuncture and related medical and businessprocedures.

BACKGROUND OF THE INVENTION

It is known in the art to use an apparatus to enhance the visualappearance of the veins and arteries in a patient to facilitateinsertion of needles into those veins and arteries. Such a system isdescribed in U.S. Pat. Nos. 5,969,754 and 6,556,858 incorporated hereinby reference as well as a paper by Zeman, H. D. et al., “The ClinicalEvaluation of Vein Contrast Enhancement”, Department of BiomedicalEngineering, University of Tennessee Health Science Center, Memphis,Tenn. 8 Feb. 2007. Luminetx is currently marketing such a device underthe name “Veinviewer Imaging System” and other information relatedthereto is available on their website, www.luminetx.com, which isincorporated herein by reference.

In this application, the use of biometrics to identify the user and/orthe patient to aid in the management and safety of processes involvingvenipuncture are described. One such biometric that is unique to thisfield is to use vein patterns to identify the individual. For example,U.S. Pat. No. 5,787,185, provides for “A method of verifying theidentity of an individual comprises capturing an image of thesubcutaneous vein pattern at a predetermined region of the individual,converting the captured image to a plurality of stored valuesrepresentative of the intensity of said image at specified relativelocations, processing the stored values to produce a second plurality ofstored values representative of the image of the vein pattern havingenhanced contrast and subjecting the second plurality of stored valuesto a thresholding process to select those above a predetermined valueand storing a set of measurements derived from the selected ones of saidsecond plurality of stored values for comparison with a correspondingset of measurements made on the individual.”

Current embodiments are large, fixed mounted devices. The presentinvention allows this capability to be integrated into a handheld deviceas well as to be used as part of the management of the venipunctureprocess and the handling of delivered drugs and drawn blood.

OBJECTS OF THE INVENTION

1) It is an object of the invention to integrate data collectioncapabilities such as bar code decoding and biometrics and use those tocontrol the use of the vein scanner

2) It is another object of the invention to combine the projection ofvein patterns with the projection of data such as text and/or icons toenhance the usability and capabilities of the device

3) It is another object of the invention to project variable dataoverlaid on the vein pattern.

4) It is yet another object of the invention to enable payment schemessuch that the practitioner can acquire the device at a reduced initialcost and pay per use or pay per user.

5) It is yet another object of the invention to gather and then projectback on the patient additional parameters of the patient such as pulseand temperature.

6) It is yet another object of the invention to connect the scanner to ahost computer to allow data collected to be stored for future uses suchas patient history and billing through wired or wireless means.

7) It is yet another object of the invention to connect to other devicesmonitoring the patient and to project the data from those monitors backon to the patient.

8) It is yet another object of the invention to project the datacollected by the invention and other devices onto an arbitrary surfaceso that the practitioner can view the data.

9) It is yet another object of the invention to allow the practitionerto avoid blood vessels when performing a procedure on a patient.

10) It is yet another object of this invention to vary the resolutionover the working area to allow certain portions of the viewed area to bescanned in higher resolutions than in other areas thereby using thelimited bandwidth of the device in an optimized manner.

11) It is yet another object of the invention to provide additionallighting on the working area to aid the practitioner to see thepatient's body.

12) It is yet another object of the invention to provide a mechanism formeasuring pulse and projecting the pulse rate back on to the body.

13) It is yet another object of the invention to provide a mechanism formeasuring blood oxygen levels and projecting the value back on to thebody.

14) It is yet another object of the invention to provide a mechanism forreading pulse rate without body contact when the target person isparticipating in exercise.

15) It is yet another object of the invention to provide the ability fora remote practitioner to perform or assist in the performance of avenipuncture.

SUMMARY OF THE INVENTION

In this application a handheld vein detection device is described withcapabilities that allow it to enhance the management of venipunctureprocesses including blood draw, venous or arterial injection orintravenous starts through the use of bar codes and biometrics; as wellas embodiments that enhance usability; and the ability to detect andrecord additional data about the patient such as the location of venousvalves, diagnostic data and re-project that data on to the patient'sbody.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1—this flowchart describes the process for taking blood samplesusing an embodiment of the invention that combines vein location withother data collection including biometrics and bar code scanning.

FIG. 2—this flowchart describes the process for injecting medicines intoa patient using an embodiment of the invention that combines veinlocation with other data collection including biometrics and bar codescanning.

FIG. 3—this exhibit shows the types of bar codes that might be used inthe invention

FIG. 4—this drawing shows examples of text and icons that might beprojected by the engine.

FIG. 5—this drawing shows how variable data can be projected to increasethe amount of data available to the practitioner.

FIG. 6A—this drawing shows a body surface being illuminated by ascanning laser pattern.

FIG. 6B—this drawing shows a part of a body being illuminated by ascanning laser pattern, and with portions of the laser light reflectedand absorbed off different structures.

FIG. 6C—this drawing shows a contrast in intensity of reflected laserlight.

FIG. 7A—this drawing shows how the device can be integrated into arobotic system.

FIG. 7B—this drawing shows the robotic control system of FIG. 7A, with adisplay and a control system.

FIG. 8 shows a person on a treadmill using the invention.

DETAILED DESCRIPTION OF THE INVENTION

Text and Iconography Projection

The preferred embodiment of the invention simultaneously capturesinformation about the target part of the body (e.g., forearm) such asvein location and then re-projects information about the captured imagedirectly over that area of capture. As previously described, in oneembodiment a visible representation of the vein position(s) is projecteddirectly on the vein locations thereby highlighting the veins and makingthem easier for the practitioner to find.

In enhanced embodiments, digital information in the form of text and/oricons can be included in the information that is re-projected on to theskin. The text and icons can be any useful information to assist thepractitioner in performing the procedure. This information may be realtime information such as vein depth or it may be patient informationsuch as patient name or it may be mistake proofing information such asthe quantity of blood needed to be drawn next so that the vial size canbe verified.

Referring to FIG. 4, text 1100 is projected that indicates informationabout the process being performed (e.g., next), the status of the system(e.g., OK) or attribute of the patient (e.g., blood pressure is 110/50).As a further enhancement, icons or pictographs 1101 can be projectedthat shows information in a graphical manner such that it doesn'trequire a common language between users. Further extending thecapabilities, combinations of text and icons 1102 can be projected thatshow both a specific value for a piece of data and a qualitativeindication of the importance of the data. In the example 1102, normaltemperature is checked, and high and low temperatures are similarlyindicated.

An alternative embodiment uses variable markings to indicate some valueabout the patient's status. In FIG. 5, an arm 1131 is shown with severalveins 1127/1132 shown. The projection area 1130 overlaps two veins whichare therefore highlighted so that the practitioner can easily find them.Additional information about those veins such as depth can be shown withsize indicators 1125/1126/1128/1129. The size of the line between theend marks can be varied to show relative or absolute depth of the vein.If additional colors or intensities are available in the embodiment, theline can be directly overlaid on the vein track 1128/1129 in a differentcolor or in a different intensity or both. Alternatively, a negativeimage in relation to the projection image can be used to show the sizebars 1128/1129. A further alternative would be to place the size bars inproximity but not on top of the imaged veins 1125/1128.

Blood Sample Lifecycle Management

The process of obtaining blood, storing it, transporting it, testing itand returning the test results has many steps, involves multiple personsand is prone to errors. Through the use of the invention many of thesemistakes can be eliminated. Referring to FIG. 1, a process for drawingblood samples is described. The process begins 1000 with theverification of the user/practitioner 1001. This verification can takemany forms. The device can be equipped with a keypad such that the usercan enter in a personal identifier such as employee id-along with anoptional pass code. The device can also have a built in token readersuch as a smart card reader or an RFID reader such that the userpresents this physical token to the device to identify themselves. Thedevice can have built-in biometrics reading capabilities such as afingerprint reader or an audio input subsystem to allow for voicerecognition. Since the device is inherently an image capturing system,image based biometrics such as vein pattern recognition and facialrecognition can be used. In most cases a single identifier would beused. However, in some circumstances, a higher level of security mightbe desired and combinations of identifiers could be used before theprocess is allowed to continue.

Once an identifier or identifiers have been acquired 1001, they can becompared to a database 1005 of valid users of the device either in alocally stored database or in the case of a scanner that is connectedeither wired or wirelessly, a remote database can be queried. If theuser isn't found in the database 1003 or if the user does not haveappropriate training or privileges for the procedure they can beprompted to try again 1002. This prompt could be in a display built intothe device, through audio feedback, through visual feedback of anindicator such as an LED, or in the preferred embodiment, through theprojection of text or icons from the scanner's projection field. If theyuser has been successfully identified 1006 then the process moves on toverifying that the patient is the correct patient.

Verification of the patient 1007 can take all of the forms describedabove for the user of the device. In addition, it is common in hospitalenvironments for a patient to wear a bar coded wrist band. The devicecan be used to scan that wrist band as a means of identifying thepatient. Once an identifier or identifiers have been acquired 1010, theycan be compared to a database 1011 of valid patients of the deviceeither in a locally stored database or in the case of a scanner that isconnected either wired or wirelessly, a remote database can be queried.If the patient isn't found in the database 1011 or if there are notorders on file for the procedure, the user can be prompted to try againor to correct the situation 1008. This prompt could be in a displaybuilt into the device, through audio feedback, through visual feedbackof an indicator such as an LED, or in the preferred embodiment, throughthe projection of text or icons from the scanner's projection field.

Now that the practitioner and the patient have been validated, a list ofblood needed and the equipment needed to perform the procedure 1013 canbe presented to the user through one of the modalities described above.

Since the invention can be used for bar code data collection, it can beused to ensure that the appropriate materials are in hand before thevenipuncture is performed. As the user selects each piece of equipment1014 they can use bar code or other means of identification such as RFIDto verify that the item 1015 is on the list of needed equipment. Theprocess repeats and prompts the user 1016 to continue with gatheringequipment until all of the equipment has been identified 1018.

Once a complete set of equipment has been verified 1019, the user canuse the vein scanner to find a vein and perform the venipuncture 1020.As the user fills the vials 1021 they can be identified again as filledand if all of the required vials have not been filled 1023, the user canbe prompted to continue 1022.

Once all of the vials are filled 1080 the user verifies that the processhas completed successfully 1075 and then packages the specimens takenfor delivery to the lab 1027/1028 and The status of the completedprocess is reported either in the documents forwarded on with thespecimens and in a preferred embodiment, this information can be updatedin to the medical records database using one of the input andconnectivity modalities previously described.

The flowchart and the associated descriptions are shown to highlight howadditional input and output modalities integrated into the vein scannercan be used to enhance the process of blood collection. However, thespecifics of the processes implemented in different medical environmentswill require changes to the process flow to meet the unique requirementsof the specific environment.

Injection Lifecycle Management

Improper or mistaken delivery of medicines is one of the leading causesof accidental injury or death in the healthcare system. In addition tothe use of the vein scanner to help identify the position of veins toaid in the taking of blood specimens, the vein scanner can be used toassist in the delivery of medicines into the patient.

In addition, an enhanced scanner can assist in the management of theinjection process in a similar way as described above for taking bloodspecimens. Referring to FIG. 2, a substantially similar process ispresented. Steps 1050-1069 are handled as previously described for steps1000-1019 in FIG. 1. While blood draw is typically handled with a singlecatheter and multiple containers, injections might use multiplehypodermics, so step 1070 is not always performed and step 1071 mightinclude multiple injections and therefore multiple uses of the scannerto verify vessel location. All of the remaining steps are substantiallyidentical to that described above.

Intramuscular Injections

A primary focus of the invention has been to locate blood vessels sothat a practitioner can access that vessel with a needle for withdrawingblood or injecting a material into the blood stream. In medicalpractice, some inject-able substances must be injected into the musclerather than into a vein. Through the use of the invention, veins can belocated for this procedure and the area between veins can be targeted bythe practitioner thereby reducing the risk of inadvertently injectingthe substance into a vein.

Image Capture

In an embodiment of the invention where the laser is scanned in apredictable and repeatable pattern, such as a raster pattern, an imageof the targeted area can be captured and stored into memory. This imagecan be of sufficient quality and resolution to allow image processingtechniques that are well known in the art to be applied to this capturedimage.

As previously described, this stored image can be used for many purposessuch as using various image processing techniques to find the veinpattern within the image. In addition to the location of the vein, withappropriate image processing software the scanner can be used to captureand present additional information about objects seen in the field ofview.

In a digital camera a photo detector array that has elements that areseparately sensitive to red, green and blue light are used with eitherambient light or a broad spectrum white light to capture the image. In alaser based system, the image being captured is based on the targetsurface's reflection of the light of the specific color (wavelength) ofthe laser being projected.

For each laser used in the system an additional color can be capturedand included in the image. In the preferred embodiment with an infraredand a visible red laser, an image can be captured based on both thereflectivity at infrared and red. Depending on the desired result, oneor both of these images can be used. For example, in a bar codeapplication, a bar code could be scanned with the infrared laser that isinvisible to the human eye. With the addition of other color lasers,more information about the target surface can be captured.

Finding Needle

Since the needle is a large object that is above the surface of the bodyprior to venipuncture, image processing software can be used to identifythe position of the needle using its different characteristics whencompared to skin and sub-skin body parts. Since the invention bothcaptures an image and projects an image, the user can be prompted withprojected feedback as to the position of the needle in relation to thenearest vein in the field of view. Since it is important that the needlepierces the vein in its center, icons such as cross hairs or arrows canbe used to guide the practitioner to the proper position. For example,right/left/forward arrows can be used to accurately guide thepractitioner to the center of the vein by showing them the direction tomove the needle. The invention is also able to use other feedbackmechanisms such as audible feedback or that of projecting text into thefield of view with prompting information.

Finding Vein

Once the image is captured from the penetrating infrared laser, manyalgorithms well known in the art can be used to find the veins. Severalthings are typical in the types of veins that one would wish to selectfor venipuncture, including that it has a sizeable segment that islinear. Therefore, a line detection algorithm can be used. Another thingthat is characteristic of the vein image being captured is that thereare edge boundaries between the area surrounding the vein and the veinitself. An edge detection algorithm such as the one described by Cannyin the IEEE Transactions on Pattern Analysis and Machine Intelligencearchive, Volume 8, Issue 6 (November 1986), Pages: 679-698, Year ofPublication: 1986, ISSN:0162-8828, can be used to find these edges.

Finding Depth

In a preferred embodiment, the output intensity of the laser (or thegain of the photo detection circuitry, or a combination of both) can bevaried from frame to frame as the scanner passes over the target area.The higher the intensity, the deeper the laser will penetrate the body.At a low setting, the veins identified will be close to the surface. Athigher settings, more and deeper veins will be identified.

By comparing the images between frames a determination can be made ofwhich veins are close to the surface of the body and which veins aredeeper. As the intensity increases and new veins become visible, theimage processing software can tag the veins seen with an indicator ofthe intensity at which they first became visible. This provides anindication of relative depth.

Several user interfaces are possible. In a system with multiple,differently colored projection lasers, veins at different depths can bedisplayed in different colors. In a system with a single projectioncolor, the lines that represent the veins could have patternssuperimposed over the vein to indicate depth such as crosshatching forshallow and solid for deep. An alternative embodiment would be to allowthe user to set what depth to look at so that only the veins of aspecific depth are presented to the user.

Bar Code

There is a significant body of knowledge on the use of image capturedevices to read bar codes such as described U.S. Pat. No. 6,223,988.Since the invention is capable of capturing an image of the necessaryresolution and quality for bar code detection, algorithms well known inthe art can be used to find and decode bar codes that are in the fieldof view.

Bar codes are commonly used to identify users (through ID cards orbadges), identify patients (through wrist bands) and to identifyequipment (through bar-coded labels) in medical environments. It is animportant extension of the invention to have it able to read bar codesso that it can be fully integrated into the work flows of the medicalenvironment.

The invention can be implemented such that it captures images of thefield of view, and stores those images into computer memory. Usingtechniques well known in the art, the captured images can be searchedfor the presence of bar codes such as those shown in FIG. 3. Both the 1Dand 2D bar codes shown in FIG. 3 could be captured by an image capturingversion of the invention. An alternative version of the invention canuse the signal from a single line of the laser scanning pattern, as itcrosses a 1D bar code as seen in the upper portion of FIG. 3, and decodethe bar code through the reflections of the marks and spaces throughtechniques that are well known in the art.

By re-using the image capture capabilities of the scanner for bar codereading a very small, tightly integrated, low cost embodiment can becreated that combines vein location and bar code scanning.

An alternative implementation of bar code scanning would be to use acommercially available off the shelf bar code scanning engine such asthose available from Hand Held Products integrated into the housing ofthe invention. This would have the advantage of keeping the veindetection portion of the design simpler and forgo the need to develop orintegrate bar code reading into the vein detection electronics andsoftware. The disadvantage is that there would be redundancies thatmight increase the size and cost of the unit.

Biometrics

As previously described, the ability to identify the user of theinvention and the patient upon which the invention will be used are veryuseful to the management of the medical procedures. Simple methods ofpasswords or PINs can be used for the user identification, and aspreviously described bar coded wrist bands can be used to identify thepatient. However, each of these approaches has its weaknesses in thatthe password or PINs can be misplaced and the wrist band is onlyavailable in a hospital environment.

Once again, the image capture capabilities of the invention can be usedfor capturing many biometric identifiers such as but not limited tofingerprint, face recognition, iris or retina recognition, and veinpattern recognition through techniques well known in the art.

There are many biometric capture devices available on the market thatare designed to be integrated into an OEM devices such as laptops. Thisincludes fingerprint modules such as those available from AuthenTec(www.authentec.com) which can be integrated into the invention. Thisavoids the complexity of the user having to ‘take a picture’ of theirfinger and allows them to simply swipe their finger on the sensor.

While fingerprint has become a common method of biometricidentification, any biometric identification device could be integratedinto the invention to allow the user and patient to be identified.

Non contact biometrics can be valuable in a medical situation. Forexample, a fingerprint would be difficult to read from the gloved handof the practitioner and the device would have to be cleaned betweenpatients if they came in physical contact with it for a fingerprintswipe. Therefore, non contact biometrics are very desirable. By adding amicrophone and associated analog to digital circuitry, sound samplingcan be included in the invention and voice recognition techniques wellknown in the art can be applied to user and patient identification.

Non-Linear Scanning Speeds

The scanning speed of a moving laser and the resolution of the capturedimage are subject to many physical limitations such as the maximum speedof the mirror, and the bandwidth of the electronic circuitry. However,it is desirable in some embodiments to have a higher resolution of theimage on a particular area of the body than the device is inherentlycapable of. One mechanism to overcome this limitation would be to reducethe area being scanned so that whatever the native resolution of thedevice is, it is being applied to a smaller physical area. This tradesoff scanning area vs. resolution.

An alternative embodiment of the device would is to change theresolution of the scanned image in a particular area of the field ofview. For example, since the practitioner would typically focus theirattention on the center of the field of view, if the device can be madeto have higher resolution at the center, the information content of theprojected image would be higher at that most important point, withoutreducing the total field of view of the device. In a scanned laserimplementation, this is done by varying the amplitude of the drivecircuit so that the mirror moves less quickly in the center and morequickly outside of the center. The increase in dwell time at the centerof the image provides higher resolution in that area. The decrease indwell time outside the center would reduce the resolution in that area.The advantage of this over the previous embodiment is that the totalfield of view is maintained while sill gaining an improvement inresolution of the targeted area.

Business Models

Most medical practitioners will have the need to draw blood or otherwisestick the patient in their normal course of practice. However, for manyof these practitioners this is not done on a regular basis. For example,in a general practitioners office this might be only two to three timesa day. This presents a dilemma. On one hand, they don't do the procedureoften enough to become very skilled, and would therefore gain anextraordinary benefit from a vein location device, but on the other handthey don't perform the procedure often enough to cost justify theacquisition of such a device.

Records of usage can be:

-   -   1. Uploaded immediately through a wireless connection    -   2. Kept in the device memory and then uploaded to a billing        system later through a wired or wireless connection    -   3. Kept in the device on a removable storage device such as an        SD card and then transferred to a billing system by removing the        card from the device    -   4. Entirely within the device by using a pre-paid billing        approach where a certain number of usages are enabled and the        device counts down until there are none left and then disables        itself until such a time as more credit is added, through a        wired, wireless or physical token as discussed above.

To overcome-this dilemma, the device can be modified to provide a peruse-type licensing model. This can be approached by keeping track of thenumber of times the device is activated in memory that is built in tothe device. Various schemes can be used to activate the device such as:

-   -   1. Enable the device for a pre-determined period of time. This        can be cheated in that there is no limit to the number of        patients scanned during that period of time.    -   2. Enable the device for an unlimited period of time after a        particular patient is identified through a biometric scan such        as vein pattern, face or voice recognition. This is more        expensive to implement, but is much harder to cheat.    -   3. Some combination of 1 and 2.        The inverse of this dilemma is an office with many practitioners        where they share the device. In such a circumstance, the benefit        of the device is very large when the entire group is considered.        It would desirable to be paid more for the device in such a        circumstance. Through the use of biometrics, the practitioner        can be identified and a record can be kept in the device of that        practitioner's access of the device. As above, various schemes        can be used to activate the device such as:    -   1. Enable the device for a pre-determined period of time. This        can be cheated in that there is no limit to the number of        patients scanned during that period of time.    -   2. Enable the device for an unlimited period of time after a        particular patient is identified through a biometric scan such        as vein pattern, face or voice recognition. This is more        expensive to implement, but is much harder to cheat.    -   3. Some combination of 1 and 2.

Data Collection

In the simplest embodiment, a vein scanner is a stand alone device thatsimply detects and projects a vein pattern back on to the skin of thepatient. In this embodiment, no data about the process or the patient isretained for future use. In an enhanced embodiment, the device can beused to collect, store, manipulate and transmit information about theuser, the usage of the device, and the patient. Also, updated controlsoftware and firmware can be uploaded to the device. In addition, datacan be transferred into the scanner that can be used as previouslydescribed to manage the processes associated with venipuncture.

The transfer of information can either be batched up so that when neededthe device can be connected to a computer system for upload anddownload, but in normal operation it is unconnected, or the device canbe always connected to a computer system either through a wired orwireless connection. There are advantages and disadvantages and costsassociated with each of these techniques that are well known.

While a bi-directional connection that allows the systems to acknowledgethat communications have been properly received, a one-way communicationscheme can be used for simple embodiments.

Wired Connectivity

The device can be connected to a computer system using a cable such ascommonly seen in bar code scanners at store checkouts. The advantage ofthis implementation is that it is typically low cost and doesn't requirethat a battery be in the handheld and eliminates the need to charge thebattery. The disadvantage is that the unit cannot be moved far from thecomputer and the cable can get in the way and easily breaks. Approacheswell known in the art can be used for cabled communication such asRS232, USB or Ethernet can be used for transport medium.

Wireless Connectivity

A wireless implementation eliminates the problems associated with acable with the tradeoff that a battery is needed in the device. Wirelesscan be implemented with well understood approaches such aspoint-to-point proprietary protocols such as seen in remote control keyfobs or standard protocols such as Bluetooth or WiFi.

Optical Connectivity

Since the device contains both a means of measuring light with its photodetector and emitting light with its lasers, these devices can also beused to transmit and receive data. Thorough the use of modulationschemes that are well known in the art, the laser can be used totransmit data to a remote receiver that could be integrated into thecradle or into a stand alone receiver. This receiver would have a photodetector system capable of detecting and decoding the modulated laserlight. It would also have an output system such as a LED or LEDs thatwould transmit a modulated light signal at a wavelength that can bedetected by the photo detector in the handheld. In this manner a two-waycommunication session can be established.

Batch Connectivity

Memory can be added to the system so that system events can be capturedand system control information can be kept in that memory. From time totime, the information collected will need to be sent to another computeror new control information will need to be downloaded to the scanner.Any of the communication techniques previously described can be used onan ad-hoc basis to connect the scanner to a computer and to transfer theinformation. When not transferring information, the scanner isdisconnected from the computer system and continues to operate in astand alone mode.

Flashlight

In many field medical situations, there is limited ambient lightavailable for performing procedures such as venipuncture. One mechanismthat a practitioner would use to improve lighting would be to use ahandheld flashlight to illuminate a specific area of the patient's body.One embodiment of the invention would be to integrate the scanningcapability into a flashlight and the inverse of integrating a flashlightinto the device.

One embodiment is that the invention be used such that the intensity ofthe projected field is bright enough to illuminate the body area withoutthe need of additional lighting during the venipuncture process. Thiscan be implemented so that the intensity is controllable by the userwith the same hand that is holding the scanner. By varying the intensityof both the dark areas that represent veins and the light areas thatrepresent the spaces between veins, and keeping the contrast between thetwo sufficiently different, the field of work can be kept well lit whilemaintaining the ability to discern the vein positions.

Integrated Scanner into a Flashlight

Most of the embodiments of the invention have been described asstand-alone devices. However, since the scan engine of the invention canbe miniaturized, it is uniquely suited to be integrated into otherdevices already in use by the practitioner. For example, the scan enginecan be built into an otoscope such that it becomes a multi-functiondevice for both looking into shaded areas of the body such as the earcanal and then used for vein location. The advantages to the user arethat they have a single device to buy and manage and a single batterycan be used.

Another device that the invention can be integrated with is aflashlight. Depending on the application, the scanner can be integratedso that the light beam and the scan/projection field are aligned alongthe same path. In this manner, the area of the body is illuminated bythe flashlight and the vein pattern is viewable in the same field. Thelaser projection will be bright enough for most applications, but theflashlight/scanner combo can contain controls that alternately switchbetween scan/project only, light only and both or other combinations ofthose modes. The intensity of both the flash light and the projector canbe controlled in these modes to ensure that the pattern remains visiblewithout becoming over-bright or too dim.

Integrated Flashlight into the Scanner

An alternative approach is to add lighting capabilities to the scanner.Finer control over the modes of the device can be accomplished in thisway. In a preferred embodiment, the scanner is implemented so thatmultiple lasers allow any color to be projected on to the body includingwhite. In this way, the field of view can be illuminated in white lightand the other colors can be used to identify the position of the veinsand to project data into the field of view. Since there is no competingillumination from a flashlight bulb, the image will be easier to read,while still illuminating the body part.

A further enhancement of the invention would be to implement anon-linear scanning pattern so that the illuminated area can be madearbitrarily wide, thereby increasing the device's utility as aflashlight while maintaining a good vein image in the center of the scanarea.

A user interface can be implemented that allows the practitioner toswitch between these modes and to modify the parameters such asintensity, field of view and field of high resolution. This userinterface can be either controls for user input or based on the distanceto the target area or both.

Telemedicine

The use of robots to provide fine control of surgical tools is wellknown in the art. In U.S. Pat. No. 7,155,316, a robot system for use insurgical procedures is described. In U.S. Pat. No. 7,158,859, a mobilerobot that provides the ability to remotely control the robot and to seethe patient, the patient surroundings and the tools in use is described.

In a normal patient encounter for venipuncture, the practitioner woulduse several senses to locate a vein and then to perform venipuncture.This would include looking for both visible and tactile indicators ofthe vein position. The invention enhances the visible feedback of theposition of the veins. By using the visual position enhancement, theability to use a tele-robot to perform venipuncture is enhanced.

The vein scanner engine can be integrated into one of these robots sothat the scanning/projection field is positioned in alignment with theend of a robotic arm which contains the needle or catheter for thevenipuncture procedure. The engine can be mounted directly to the armthat contains the needle or it can be mounted to a separatelycontrollable arm.

The engine can work in one of three modes. It can work as it normallydoes such that the acquisition of the vein pattern and the projection ofthe vein pattern is directly on the patient's skin. In this mode, thecameras that are already on the robot can view the pattern on the skinand send that back to the remote operator on the screen that is alreadyprovided for the remote operator.

In a second mode, the detected vein pattern is captured and then ratherthan projecting the pattern back on to the patient, the pattern is sentto the remote practitioner and is shown to them on a screen. In thismode, there are several possible embodiments. One is that the pattern ofveins can be overlaid on the video display of the patient's body. Inthis manner, what they see on the screen is very much like what theywould see on the body. The advantage of this is that the image from thevein scanner can be enhanced and made brighter than it would be in thefirst mode.

In a third mode, a combination of the first two modes can be used thatallows the practitioner to switch between the modes or for both modes tobe used simultaneously on two different screens or windows on a singlescreen.

Referring to FIGS. 7a and b , a robotic control system 1204 is shownwith a controllable articulated arm 1200 holding a medical device 1205.The remote medical practitioner 1207 uses a corresponding control system1206 to move the arm 1200 and the medical device 1205 to perform amedical procedure on the patient 1201. The remote system 1206 has adisplay 1208 that the practitioner uses to view the patient 1201 and theaction of the medical device 1205. Typically this is performed by acamera mounted to the medical device 1205 or to the arm 1200. Ourinvention adds a vein scanner device 1202 to either the medical device1205 or the arm 1200. The vein scanner is arranged in such a way thatthe scanned area overlaps in a known orientation with the medicaldevice. In a preferred embodiment the medical device is a syringe andthe enhanced vein pattern is used to properly position the syringe forvenipuncture. The invention enables this by either projecting thepattern on the patient's body such that it is viewed by the camera andseen by the practitioner on the remote display 1208 or alternatively asecond display is mounted along with the camera display 1208 so that adigital version of the vein pattern can be seen or alternatively asingle display is used with the digital version of the vein patternoverlaid over the camera view of the patient.

Non Contact Photoplethysmography

Pulse oximetry is a non-invasive method of measuring arterial oxygensaturation. The use of an infrared light source and a red light sourcealong with a photo detector in a finger clip arrangement to measurepulse and oxygen levels in blood are well known in the art. The basisfor the measurement is the differential absorption between oxygenatedhemoglobin and non-oxygenated hemoglobin of the two differentwavelengths of light. The traditional technique for performing thismeasurement requires contact with the body and relies on thetransmission of the light through an area of the body with a small crosssection such as a finger or an earlobe. By alternating between the redand infrared light sources and measuring the level of the light that ispassed through a body part, a waveform that is known as aphotoplethysmograph (PPG) is captured. Through signal processingtechniques that are well known in the art, oxygenation levels and pulserates can be calculated.

Several articles and patents have been published that use non-contacttechniques to measure the necessary waveforms by replacing the photodetector with a remote device such as a CMOS camera. U.S. Pat. No.6,491,639 describes the use of a light sources and the photo detector inthe same plane eliminating the need for a small cross section part ofthe body to be used for measurement of the necessary waveforms. Thisdesign relies on the internal reflections of the body such that thelight is directed in to the body and then reflected out of the bodyrather than completely passing through a small cross section portion ofthe body.

In the article by Humphreys, K. et al, “A CMOS Camera-Based PulseOximetry Imaging System.” Proceedings of the 2005 IEEE Engineering inMedicine and Biology 27th Annual Conference (2005). 7 Feb. 2007, theydescribe a non-contact pulse oximetry system that uses a CMOS camera asthe detector. In this design, the detector is held at a distance fromthe body and a bounding box is selected in the captured image. Theaverage intensity of the bounding box is used as a proxy of the photodetector value that would be found in a contact pulse oximeter. Byplotting the changing value of the average intensity of that locationover time a PPG is derived that can be used to measure oxygenation andpulse using the same techniques as previously described.

Our micro vein enhancer invention uses scanned lasers to capture apattern of veins below the surface of the skin and then re-projects avein pattern image directly back on to the body. In one embodiment thoselaser light sources are visible red for projecting the image andinfrared for detecting the veins. The vein detection relies onabsorption characteristics that are related to those used in pulseoximetry in that the infrared light is absorbed differentially byhemoglobin than surrounding tissues.

Furthermore, we have previously described how a micro vein enhancer canbe used to capture images based on the light transmitted by the lasersand reflected back to the micro vein enhancer's photo detectorcircuitry. Through the combination of these techniques, a miniature veinenhancer can be extended to read pulse and oxygen levels without contactwith the patient.

Referring to FIG. 6a , view of the body surface 1150 is beingilluminated by the scanning laser pattern 1160. Since information mustbe collected separately from each laser wavelength, a mechanism isrequired for the system to differentiate the reflected energy from eachlaser. One mechanism is to use optical filters and two photo detectors,each responsive to only one of the lasers. Another mechanism is topolarize the lasers so that two photo detectors, each sensitive to onlyone of the laser's polarization.

A further mechanism is to project using both the visible red andinfrared lasers in an alternating pattern. The alternation can behandled in multiple ways. Possibilities include the lasers time slicedso that short pulses of each laser are alternated while the laser scans.Alternatively, the lasers can be switched between scan lines with rightto left with one laser and left to right with the other laser.Alternately, the lasers can be switched on some multiple of scan linesor on alternate complete passes of the scan area.

Referring to FIG. 6b , a part of the body 1153 is illuminated by thescanning laser pattern 1154 from the vein enhancer. Portions of thelaser light are reflected and absorbed off different structures of thebody. The portion that is reflected 1155 is measured by the photodetector of vein enhancer. The laser projects a point source on to thebody. Therefore the reflected signal is characteristic of a small areaof the body. Since the PPG needs to be representative of both venous andarterial blood, the small point source reflection may be insufficientfor detecting the PPG.

Referring back to FIG. 6a , the scanned area 1160 is broken down in to anumber of smaller areas (e.g., 1151/1152) that are sized to capture alarge enough area of the body such that an adequate PPG can be detected.The system can dynamically change the size of the smaller areas suchthat they are sufficiently large to obtain an adequate return signalregardless of the distance of the scanner from the body. The system thenaverages the returned signal from all of the pixels in the smaller areasand records the values. By keeping track of these values for the samelocation, over time, a PPG is generated.

Since the preferred embodiment is a handheld device, the motion of thedevice in relation to the patient must be allowed for. In the simplestembodiment, since the device is breaking the scan area down into aseries of subsections and generating the PPG from the subsections andthere would be similar return signals from these subsections, the motioncan be ignored. However, if the motion becomes too severe or if the areabeing imaged is heterogeneous, then the system can use digital oroptical image stabilization well known in the art to maintain alignmentfrom frame to frame. An alternative method would be to keep PPGs fromall of the subsections, then as the hand moves, the system would use thePPG from areas that still remain in view.

Non Contact Pulse Measurement

Many commercially available exercise machines such as treadmills andbicycles provide the capability to measure pulse rate. Knowledge of thecurrent pulse rate is very valuable for managing excursive intensity.One commonly seen embodiment relies on hand contact with electrodes thatare used to measure heart rate. In many situations, such as running, itis difficult or dangerous to maintain contact with the electrodes.Another common embodiment uses a chest strap that measures heart rateand then wirelessly transmits it to the exercise machine so that thevalue can be displayed. This requires that the user acquire thisseparate device in order for pulse rate to be displayed. In a preferredembodiment of the invention, a capture only scan engine is mounted inproximity to the user such that the scanning pattern is oriented suchthat it strikes an uncovered portion of the body such as the hands,arms, neck or face. As described previously, the PPG waveform can becaptured and the pulse rate can be fed back into the exercise machineand displayed to the user.

Referring to FIG. 8, a person is shown exercising on a treadmill. Atypical treadmill is composed of the bed 1305 which houses a movingbelt, an upright 1302 at the front of the treadmill and a combinationcontrol panel, display panel and handle at 1303. The invention needsaccess to bare skin and therefore needs to be mounted in proximity totypically uncovered locations such as the legs 1310, the arms 1309 orthe neck 1312 and head 1308. In addition, to normally uncovered bodyparts during exercise, in some embodiments it would be desirable for thetorso 1313 to be bare or for a shirt made from materials that aretransparent to the wavelength of the scanning light to be worn. Variousembodiments of the invention can have at one or more of locationsincluding a laser scanner engine 1304 mounted on the treadmill upright1302, or an engine mounted in the display panel 1303. In addition, anadditional upright 1307 can be added to the treadmill to allow for ascanner engine 1306 to be mounted above the standard parts of thetreadmill. Given that the person will typically be moving, it ispreferred that the scanner target a part of the body that moves theleast. Therefore, the preferred embodiment would target the upper partof the body rather than the legs or the arms. Given that the pulsemeasurement application requires much lower resolution than theprojector application described elsewhere, the full travel of the movingmirror can be used to steer the measurement zone over a fairly widerange of locations. This agility provides two benefits. One, the beamcan be steered to the general desired location and the beam can be movedin synchrony with the movement of the body during exercise. Beampositions 1300, 1311 and 1301 show nominal center points for the beam.However, they can be steered in real time as desired within the generalarea of the center point.

1. A portable handheld vein-image-enhancing device, for use in selectiveimaging of subcutaneous veins of a target surface, said devicecomprising: a first laser configured to emit a beam of light at a firstwavelength; a second laser configured to emit a beam of light at asecond wavelength being different than said first wavelength; a scannerconfigured to scan said beams of said first and second wavelengths oflight onto the target surface; a photo detector configured to receivesaid first wavelength of light reflected from the target surface as acontrasted vein image formed by differential absorption and reflectionby subcutaneous veins and surrounding tissue therein; said photodetector configured to convert said contrasted image into a signal; saidsecond laser configured to receive said signal, and said second laserand said scanner thereby configured to project said contrasted veinimage onto the target surface using said second wavelength of light, forthe veins of said contrasted vein image to be projected onto the targetsurface directly over the imaged subcutaneous veins; and a userinterface and electronic circuitry configured to permit adjustment ofone or more imaging parameters for said selective imaging by saiddevice.
 2. The portable handheld vein-image-enhancing device accordingto claim 1, further comprising a memory, and wherein said user interfaceand electronic circuitry is further configured to permit said adjustedone or more imaging parameters to be stored in said memory.
 3. Theportable handheld vein-image-enhancing device according to claim 1,wherein said user interface and electronic circuitry are configured topermit adjustment of a vein size parameter to set a vein size to beimaged by said device.
 4. The portable handheld vein-image-enhancingdevice according to claim 1, wherein said user interface and electroniccircuitry are configured to permit adjustment of a field of viewparameter to set a size of the field of view to be imaged by saiddevice.
 5. The portable handheld vein-image-enhancing device accordingto claim 1, wherein said user interface and electronic circuitry areconfigured to permit adjustment of a resolution parameter to set a sizeof a field of high resolution for said projected image.
 6. The portablehandheld vein-image-enhancing device according to claim 1, wherein saiduser interface and electronic circuitry are configured to permitadjustment of a brightness projection parameter to set a brightness ofsaid projected image by said second laser.
 7. The portable handheldvein-image-enhancing device according to claim 1, wherein said userinterface and electronic circuitry are configured to permit adjustmentof a laser output intensity parameter to set a depth to be penetrated bysaid first laser for said imaging by said device.
 8. The portablehandheld vein-image-enhancing device according to claim 1, wherein saiduser interface and electronic circuitry are configured to permitadjustment of a persistence of vein lock parameter to aid in thediscrimination of veins from other structures for said imaging by saiddevice.
 9. The portable handheld vein-image-enhancing device accordingto claim 1, wherein said scanner comprises one or more mirrorsconfigured to oscillate in two orthogonal directions.
 10. The portablehandheld vein-image-enhancing device according to claim 1, wherein saidfirst wavelength of light comprises an infrared wavelength of light, andsaid second wavelength of light comprises a visible red wavelength oflight.
 11. A portable handheld vein-image-enhancing device, for use inselective imaging of subcutaneous veins of a target surface, said devicecomprising: a first laser configured to emit a beam of light at a firstwavelength; a second laser configured to emit a beam of light at asecond wavelength being different than said first wavelength; means forscanning said beams of said first and second wavelengths of light ontothe target surface; a photo detector configured to receive said firstwavelength of light reflected from the target surface as a contrastedvein image formed by differential absorption and reflection bysubcutaneous veins and surrounding tissue therein; said photo detectorconfigured to convert said contrasted image into a signal; said secondlaser configured to receive said signal, and said second laser and saidmeans for scanning thereby configured to project said contrasted veinimage onto the target surface using said second wavelength of light, forthe veins of said contrasted vein image to be projected onto the targetsurface directly over the imaged subcutaneous veins; and a user inputcontrol means and electronic circuitry configured to permit adjustmentof one or more imaging parameters for said selective imaging by saiddevice.
 12. The portable handheld vein-image-enhancing device accordingto claim 11, further comprising a memory, and wherein said user inputcontrol means and electronic circuitry is further configured to permitsaid adjusted one or more imaging parameters to be stored in saidmemory.
 13. The portable handheld vein-image-enhancing device accordingto claim 12, wherein said user input control means and electroniccircuitry are configured to permit adjustment of a parameter from thegroup of parameters consisting of: a vein size parameter to set a veinsize to be imaged by said device; a field of view parameter to set asize of the field of view to be imaged by said device; a resolutionparameter to set a size of a field of high resolution for said projectedimage; a brightness projection parameter to set a brightness of saidprojected image by said second laser; a laser output intensity parameterto set a depth to be penetrated by said first laser for said imaging bysaid device; and a persistence of vein lock parameter to aid in thediscrimination of veins from other structures for said imaging by saiddevice.
 14. The portable handheld vein-image-enhancing device accordingto claim 13, wherein said first wavelength of light comprises aninfrared wavelength, and said second wavelength of light comprises avisible red wavelength.
 15. A portable handheld vein-image-enhancingdevice, for use in selective imaging of subcutaneous veins of a targetsurface, said device comprising: means for imaging the subcutaneousveins of the target using a first wavelength of light and for projectingsaid vein imaging onto the target surface using a second wavelength oflight, for the veins of said vein imaging to be projected onto thetarget surface directly over the subcutaneous veins; and user inputcontrol means and electronic circuitry configured to permit adjustmentof one or more imaging parameters for said selective imaging by saiddevice.
 16. The portable handheld vein-image-enhancing device accordingto claim 15, further comprising a memory, and wherein said user inputcontrol means and electronic circuitry is further configured to permitsaid adjusted one or more imaging parameters to be stored in saidmemory.
 17. The portable handheld vein-image-enhancing device accordingto claim 16, wherein said user input control means and electroniccircuitry are configured to permit adjustment of a parameter from thegroup of parameters consisting of: a vein size parameter to set a veinsize to be imaged by said device; a field of view parameter to set asize of the field of view to be imaged by said device; a resolutionparameter to set a size of a field of high resolution for said projectedimage; a brightness projection parameter to set a brightness of saidprojected image by said second laser; a laser output intensity parameterto set a depth to be penetrated by said first laser for said imaging bysaid device; and a persistence of vein lock parameter to aid in thediscrimination of veins from other structures for said imaging by saiddevice.
 18. The portable handheld vein-image-enhancing device accordingto claim 17, wherein said first wavelength of light comprises aninfrared wavelength, and said second wavelength of light comprises avisible red wavelength.